Bioroute Production Of Biodiesel Using Cerbera Odollam Oil In Packed Bed Reactor
Loading...
Date
2011-12
Authors
Rahman, Siti Norrahmah Ab
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Diminishing reserves of fossil fuels and arising of food crisis recently have
drawn attention for researchers to produce an alternative fuels. Biodiesel which is
made from vegetable oils, animal fats or microbial oils is one of the attractive
alternative fuels due to this concern. Other than that, biodiesel is an environmental
friendly fuel which emitted less greenhouse effect gas. Cerbera odollam oil was
determined as a non-edible feedstock for biodiesel production. The enzymatic
transesterification of Cerbera odollam oil as a feedstock has been studied in the
present research.
Cerbera odollam oil has been extracted using n-hexane solvent in a soxhlet
extractor. The enzymatic transesterification were carried out in a batch system to
screen the most efficient enzyme among Lipozyme RM IM, Lipozyme TL IM and
Novozyme 435 based on the highest fatty acid methyl ester (FAME) yield in the
process. The best organic solvent used in this reaction was also determined in a batch
process between tert-butanol and n-hexane to eliminate the inhibition of methanol in
the reaction. Important parameters like temperature, speed agitation, enzyme
concentration, methanol to oil ratio and solvent to oil ratio in enzymatic
transesterification reaction were optimized by using response surface methodology
(RSM) based on central composite design (CCD). The kinetic studies of enzymatic
tansesterification were carried out in this research. Enzymatic transesterification of
Cerbera odollam oil reaction was also studied in a packed bed reactor (PBR) for a
continuous process. The effect of mass transfer in the PBR was also studied.54% of Cerbera odollam oil was extracted from the seeds. Lipozyme TL IM
and tert-butanol were found as the suitable enzyme and organic solvent in this study.
67.05 % FAME yield was obtained using a combination of Lipozyme TL IM and tert
butanol. The transesterification reaction of Cerbera odollam oil can reach up to
94.75 ± 2.43 % FAME yield with the optimized condition as suggested by RSM
(R2=0.99) ; 4.1 w/w% enzyme based on oil weight, 1:5.1 oil to methanol molar ratio,
1:2 solvent to oil volume ratio, temperature of 45°C and 200 rpm agitation speed. By
kinetics study of enzymatic transesterification of Cerbera odollam oil, a model based
on Ping Pong Bi Bi with inhibition by methanol was found to fit the initial rate data
and the kinetics parameters were evaluated by non-linear regression analysis. The
maximum reaction rate, Vmax= 17.37 mmol/ml.min, Cerbera odollam oil binding
constant, Km1=3.32 mmol/ml and methanol binding constant, Km2=3.00 mmol/ml
were obtained. The Cerbera odollam oil transesterification in PBR can reach up to
86% FAME yield with 0.60 ml/min feed flow rate and 8 cm PBR height. In mass
transfer study, models for FAME yield showed very good agreement between mass
transfer model and the experimental data obtained from PBR operation, showing that
in this study the FAME yield was mass transfer controlled (R2= 0.95). The high
FAME yield in batch and continuous operation as well as the fuel characteristic
meeting the standard of biodiesel proved that Cerbera odollam oil can be a
promising feed stock for enzymatic transesterification process.
Description
Keywords
Biodiesel fuels